Abigail hides from a Mook behind a butcher's counter. The butcher first tells her that she has to leave, but she says she's hiding from her ex-husband, gesturing to the large, muscular man. The butcher tells her she can stay as long as she wants.
It's a rather small, blink-and-you'll-miss monent. Just as the group finds the treasure, Ben and his dad share a hug.
Before that, when the found the fake room and Ben sinks into a Heroic BSOD. First Patrick, then Abigail step in to help him out of his funk.
Ben: (distraught) I just... really thought I was gonna find the treasure.
Patrick: Okay. Then we just keep looking for it.
Abigail: I'm in.
And when Ben tells his dad that he was right about the treasure being a wild goose chase, Patrick responds with "No Ben, you were right. This room is real and that means the treasure is real. We're in the company of some of the greatest minds in history because you found the clues they left and understood their meaning."
The mere fact that the "National Treasure" of the title isn't gold or jewels but history — scrolls from Alexandria and statues from Egypt, precious treasure of civilization thought lost during the Dark Ages...holy cow, man.
In National Treasure 2 - Riley, when trying to convince the rest of the treasure hunters to trust him on the President Secret Book myth:
Riley: "Ben, if it was you trying to convince me...you'd have less evidence and I would already believe you."
Mr. and Mrs. Gates' reconciliation.
Riley meeting a cute girl who actually read his book, and is an actually fan of his (not just somebody mistaking him for Ben).
Cute Girl: I recognize you from your book. Will you sign it?